Gravure print quality of uncoated mechanical printing papers - Physical and optical properties of printed and unprinted papers were compared

Twenty uncoated mechanical printing papers, fi om newsprint to SCA, were pr inted hy gravure. Physical and optical properties of printed and unprinted papers were compared to the subjective ranking. Across a wide range of samp les, subjective judgements of print quality correlated reasonably well with Print Surf roughness and with unprinted gloss. Correlations were poorer wi thin a single grade. Microscopic cross-sections of the best samples showed uniform coverage of the thick ink film, while cross-sections of poor sample s showed ink films that were highly variable in thickness. All samples were printed on the same side of die press, so sidedness problems belong solely to the paper: Top-to-bottom, differences in correlations may be an inheren t paper structural problem, which should be addressed in future work.